Vehicle suspension



Feb. 2, 1943. c. c. UTz

VEHICLE SUSPENSION vFiled Oct. 30, 1940 4 Sheets-Sheet 1 INVENTOR fierCf zzz.

ATTORNEY5. l

/f BY Feb. 2, 1943. c. c. UTz

VEHICLE SUSPENSION 4 Sheets-Sheet 2 Filed Oct. 30. 1940 INVENTOR Kiefferl/zzz. BY??` l l/Zr ATTORNEYS.

Feb. 2, 1943., c. c. mz 2,309,811

VEHICLE -SUSPENSION Fiied 001'.. 50, 1940 4 Sheets-Sheel'I 3 lNVENTORATTORNEYS- Feb. 2, 1943. c. c. uTz

VEHICLE sIJsPE1-rsIoN- 4 Sheets-Sheet 4 Filed Oct. 50, 1940 IINIIWI 1K2' (Zea-zer a INVENTOR A ATTORNEYS- Patented Feb. 2, 1943 2,309,811VEHICLE sUsPENsroN Chester C. Utz, Detroit, Mich., assigner 'to ChryslerCorporation, Highland Park, Mich., i a corporation of DelawareApplication October 30, 1940, Serial No. 363,529

rc1.' asc-124) 3 Claims.

This invention relates to `vehicle spring suspensions, particularly rearsuspensions, for vehicles employing coil springs as the suspensionmedium at the rear thereof.

During recent years the problem of providing passenger automobiles withimproved riding qualities has received much attention and steadyimprovement has been effected, principally by lowering the spring ratesand utilizing tires of i low pressure. Because of the comparatively highcruising speeds of present day automobiles and the prevalence of pavedroads, a major portion of the effort expended has been directed towardproviding the car withan improved "boulevard ride. 'I'here are, however,many miles of unpaved highways which must still be driven over, and manyvehicle suspensions which give entire satisfaction at high and lowspeeds on smooth roads are found wanting when the vehicle is driven overrough pavement, cobblestones, washboard" gravel, and the like. When thevehicle is driven over such roads, the radiator ornament, instrumentpanel, door windows and other parts of the car are frequently subjectedto vibration which is usually accompanied by jolting of the body and isvery annoying to the passengers.

This phenomenon isreferred to by automotive engineers as shake, whichterm is generally used in the art to denote vibratory movements of avehicle or parts thereof of a frequency of from two to fifteen cyclesper second.

It has been determined after considerable research devoted to thesubject that the principal cause of shake in an automobile resides inthe rigid connection between the suspension members and the axle housingat the rear of the car which connections transmit the transversevibratory movements of the axle directly to the frame.

The theory which suggested the presently d'e. scribed mode of attack onthe problem of reducing shake arises from the geometry of theconventional rear suspension. In such a suspension, the leaf springs areshackled to the frame at one end and pivoted thereto at the other endand are rigidly tied to the axle housing. When one rear wheel rises inpassing over a bump, the rear axle and wheels pivot about the point ofcontact of the undisturbed wheel with the ground. The spring seats onthe axle travel on arcs which have considerable horizontal components.The horizontal displacements of the spring seats are, however, not quiteequal, but both are of the order of x/4, inch for a bump 1 inch high andare in the same direction. The rear springs and tires are elastic, bothunder vertical and transverse forces, and as the mass of the car bodyand frame is large compared to that of the rear axle, the immediateeffect of the bump is to produce small displacement of the body, greaterdisplacement of the axle, and comparatively large elastic deflections ofthe springs andtires. These deflections, of course, involve the storageof energy in these members which will be returned in the form ofrebound, and unless high damping is present, will beapparent as avibration of the springs and attached masses. The low rate of thesprings vertically, and the damping provided by the shock absorbers,control the vertical vibration satisfactorily but the transversevibratory forces applied to the axle arevsubstantially unchecked.

Applicant has found that the substitution of coil springs and radiusarms together with the 'introduction of links between the axle and thearms, pivoting at either and about axes parallel with the center line ofthe vehicle, in eilect, suspends the whole rear end of the vehicle as apendulum and permits lateral movement of the body and springs relativeto the axle and wheels.

Thus, under the bump conditions described above, the transverse motionof lthe axle is taken up by swinging of the links, and the failure ofthe bodyto follow the axle produces negligible energy storage in thesprings and tires. The impressive reduction in shake experienced withthe use rof my invention (in the order of at the radiator ornament andwindows and 12% to 15% at the instrument panel) must then be attributedto the great reduction in the aforesaid vibratory forces.

The improved construction described and claimed'herein is alsoadvantageous in that it entirely eliminates sidewise creeping of thevehicle on washboard roads. When a vehicle with a conventional leafspring drive axle suspension is driven over a washboard road there is acontinuous creep of the rear end toward the ditch. I'his is due to thefact that rocking of the axle about the propeller shaft as a center isnecessarily accompanied by a change in wheelbase at each side of thecar.

For example, consider the conventional rear suspension which has theaxle suspended from the frame by a pair of leaf springs pivoted to theframe at their' front ends and shackled to the frame at their rear ends.When the right rear wheel goes upwardly and the left rear wheeldownwardly, the right end of the axle shifts rear'- wardly of thechassis and the left end of the axle shifts forwardly thereof. This isdue to the -fact that the arc of travel of the axle is about the wheelsunder such conditions is therefore directed toward the right hand ditch.This phenomenon is common on cars equipped with conventionalleaf springrear axle suspension and is particularly noticeable and. annoying when arelatively soft suspension is used.

With my improved construction. the axle is held in a positionperpendicular to the longitudinal center line of the chassis under allconditions and sidewise creep is entirely absent.

Accordingly, it is the principal object of the invention to eiect areduction in the shake tendency of an automotive vehicle by simple,effective.

and economical means.

Another object is to provide improved means for connecting the rearsprings of a vehicle to up of a stamped channel member I9 to which ilwelded or otherwise suitably secured a second stamped channel member 20.

The members I 9 and 28 are respectively secured to the brace members I'Iand I6 by pivot pins 2 I-22, rubber bushings like the one shown at 23being provided to assure quiet operation and eliminate need forlubrication. Relnforclng bracket structures 24-25 are secured to themembers I'I-I 6 respectively at the vicinity of the pins 2I-22 forstrengthening the structure at these points. The pins 2I22 arepreferably disposed in alignment and parallel to the longitudinal centerline ofthe frame.

As can be seen in Fig'. 2, the arm portion Il extends slightlyrearwardly of its connection with the portion 20 to provide a seat for acoll spring 26 which is secured thereto by means of a suitable clamp 21and bolt 29, rubber pads 2l vbeing inserted between the spring and clampto insure quietness. At the top, the spring 26 is secured to the chassisside sill I5 by a similar clamping device.V n

The axle I0 is secured to each of the arms I8 by a pair of swingingshackle links 30. The latter are of forged construction and arepivotally the axle thereof which reduces the transverse vibratory forcestransmitted to the body.

An additional object of the invention is to provide improved means forattaching the rear axle of a vehicle to the springs thereof whereby thebody of the vehicle is suspended for lateraljpendulum movement relativeto the axle.

A further object is the provision of improved means for mounting theaxle on the chassis frame in such manner that the axle remainsperpendicular to the center line of the frame under all conditions ofoperation.

Further objects and advantages of the invention will become apparentfrom the following description which is directed to a preferred form ofthe device.

In the drawings which accompany the following specification,

Fig. l i-s a plan view of one half of the vehicle frame at the rearthereof showing the essential parts of my novel spring suspension.

Fig. 2 is a part-sectional view taken along the line 2--2 of Fig. 1 withparts broken away to show details.

Fig. 3 is a rear elevational view on a smaller scale taken along line3-3 of Fig. 2.

Figs. 4, 5 and 6 are views similar respectively to Figs. 1, 2 and 3 andillustrating a modified form of the invention. p

Fig. '7 is a detail view of the aforesaid modified form with partsbroken away to illustrate the rubber bumper construction.

In the drawings in which reference numerals designate correspondingparts referred to herein, the rear drive axle IIJ of the vehicle isProvided with the usual differential housing II and propeller shaft I2.The drive wheels I3 are mounted on the axle in the usual manner and areadapted to be driven from the differential gearing by axle shafts I4.

The chassis side sills I5 are connected by a pair of transversestructural brace members I6 and I1, the former being arched downwardlyand the latter being arched upwardly as illustrated in Figs. 2 and 3.

Secured to the transverse brace members I6-I1 at each side of thevehicle is an arm I8.

connected to the integrally extending bosses 3| of a bracket 32 carriedby the axle housing, a rubber bushing 33 being used for quietness. Attheir lower ends the links 38 are similarly' pivotally connected to aV-shaped bracket 34 rigidly secured to the arm I8 just forwardly of theconnection of the portion 20 thereto.

A telescoping shock absorber 35 is pivotally secured to the frame andsuspension arm at 36 and 31 respectively and assists in controlling theswinging of the arm I8 about the axis dened by the pivot pins 2I-22. Arubber bumper 38 carried by the arm portion I9 directly below the axlehousing limits the transverse swing of the axle and cushions the shockduring severe rebound thereof.

During operation of the vehicle, the axle I6 rises and falls relative tothe frame under lcontrol of the springs 26 and shock absorber 35, theshackle links 38 acting to permit the arms I8 to swing on a true arcabout the axis of pins 2I-22. The links 30 also permit the axle alimited amount of .transverse swinging about the axes of the bosses 39of bracket 34.

Thus it may be seen that while the axle is relatively free for swingingin a vertical plane and in a transverse horizontal plane, it ismaintained exactly perpendicular to the longitudinal central plane ofthe chassis at all times and under all conditions.

Figs. 4 to '7, inclusive, illustrate a slightly modi- I fied form of theinvention which accomplishes v the shock absorber is bolted at 31.

This arm is of substantially V-'shape and is built 75 A rubber bumper 4Iis xed to the frame side sill directly above the axle as shown in Fig. 5to prevent bottoming of the frame on the axle housing and a secondbumper 42 carried by a bracket 43 which is welded o'r otherwise securedto the axle housing'llmits the downward travel of the axle relative tothe frame. By referring to Fig. 7 it may be seen that as the axle islowered relative to the frame, the bumper 42 moves toward the inside ofthe channel I9. When the bumper engages the inner web of the channel,the axle has dropped the maximum distance permitted.

Having thus described a specific embodiment of my invention, I wish topoint out that, by so doing, I do not intend to limit the invention inthe broader aspects thereof except as defined in the claims appendedbelow.

I claim:

l.- In a suspension for a vehicle having a frame and an axle, means ateach side of said frame for mounting said axle on said frame forvertical' swinging relative thereto comprising an arm pivoted at one endon said frame and extending beneath said axle; a spring carried by theother end of said arm and connected to said frame for controlling theswinging of said axle; a second arm xed to said rst arm at a pointbetween said spring and said pivot and pivoted to said frame; a shackleconnecting said axle and saidl arms at their point of connection, and aresilient bumper element carried by said axle on the under side thereofand adapted to be engaged by said second arm thereby tollimit downwardmovement of said axle relatively to said frame.

2. In a suspension for a vehicle having a frame and an axle, means formounting the axle on the frame for Vertical swinging relative theretocomprising an arm pivotally connected to said frame at each side thereofand extending beneath said axle; a plate carried by said arm; a coilspring disposed between said plate and said frame; shackle meansconnecting said plate and said axle; and a rubber bumper carried by saidaxle and adapted to engage said arm thereby to limit the swingingthereof.

3. In a vehicle suspension, a frame; an arm pivoted on each side of theframe for vertical swinging relatively thereto; an axle vdisposedtransversely of the frame; said arms each having a portion extendinggenerally longitudinally of the frame beneath said axle and terminatingrearwardly of the axle in a spring seat; a coil spring carried by eachof said spring seats for yieldably controlling swinging of the arms, andshackle means connecting each of the arms with the axle whereby the axleis permitted limited r movement transversely of the vehicle.

2 CHESTER vC. U'rz.

